Stormwater Pollution

What is stormwater pollution?

Stormwater is water from rain that does not soak into the ground. It flows over paved areas like streets, sidewalks, and parking lots, as well as roofs and sloped lawns. As it flows, stormwater collects and carries pollutants such as litter, pet waste, pesticides, fertilizers, and motor oil. This "toxic soup" then flows through a massive system of pipes and channels directly into our local waterways and the ocean.

What is the difference between the storm drain system and the sanitary sewer system?

The storm drain system and sanitary sewer system are both large systems of underground pipes. This leads to the common misconception that the systems are the same or are connected. They are in fact separate systems and serve different purposes.

The sanitary sewer system transports domestic sewage to a treatment plant. Domestic sewage includes wastewater from household and commercial plumbing, such as toilets, showers, and sinks. In Temple City, sewage travels from private sewer pipes on each property into the City’s sanitary sewer system and then into the Los Angeles County sanitary sewer system, which eventually carries it to the San Jose Creek Water Reclamation Plant located in unincorporated Los Angeles County adjacent to the City of Whittier. There, contaminants are removed from the sewage through a multi-stage process that includes settling, filtering, and biological and chemical treatment. The treated water is then discharged into local waterways or used as reclaimed water.

The storm drain system, on the other hand, was designed to prevent cities from flooding. Its purpose is to quickly transport rain runoff (stormwater) away from the city and into the nearest waterway, without treatment. Since there is no treatment, any pollution carried by stormwater also enters our waterways untreated.

The diagram below shows the difference between the sanitary sewer system (on the left) and storm drain system (on the right).

Click for larger image

Where does our stormwater go?

In Temple City, stormwater enters the local storm drain system where it drains to the Rio Hondo and flows to the Los Angeles River and eventually the Pacific Ocean.

What are the effects of stormwater pollution?

Stormwater pollution can have an adverse impact on our community’s health and environment as well as its local waterways and the ocean.

Health and Environment

Stormwater pollution poses a health threat to people who swim or fish in the ocean. Rain events can produce runoff with high amounts of bacteria, causing beach closures. This impacts recreational uses for the ocean and our local waterways, such as swimming, beach tourism, fishing, and boating.

Stormwater pollution can be toxic to marine life in the ocean and our waterways. Toxic pollutants can also be passed along the food chain. This can result in the contamination of locally caught seafood, making it unsafe for consumption.

Local Community

Local storm drains clogged with litter and debris can impact the local community. These "nests" of trash and debris can attract pests and rodents, create foul odors, clog the storm drain system, and cause flooding. In addition, clogged catch basins are unsightly and can affect neighborhood aesthetics and property values.

What are some of the ways I can prevent stormwater pollution?

To ensure the safety and enjoyment of our local waterways and the ocean, it is important to keep our storm drains free of pollutants. Below are some helpful tips on how to prevent stormwater pollution.

Vehicle Maintenance: All used motor oil, filters, and other automotive fluids should be disposed of properly and should never be dumped on the ground, street, gutter, or storm drain. Do-It-Yourselfers that change their own oil are encouraged to dispose of used motor oil and filters at their nearest recycling center. For more information on used oil recycling and to locate a recycling center, visit the CalRecycle web site.> Tips for the Home Mechanic brochure

Pet Waste: Pick up pet waste. When pet waste is left on the ground, harmful bacteria can wash down the storm drain and into the ocean resulting in contaminated and closed beaches.> Tips for Pet Care brochure

Green Waste: Use a broom instead of a hose to sweep garden clippings. Excess water from sprinklers or a garden hose can pick up pollutants and enter the storm drain.> Tips for Landscape & Gardening brochure